Astrology has long been used in the medical professions for the diagnosis of illness and to identify potential illness. Nicholas Culpeper (1616-1654) the famous herbalist and physician used astrology alongside his herbal medicines. The birthchart would be used for the diagnosis and Culpeper would treat the illness appropriately. He is known as saying, "Only astrologers are fit to study medicine and a medical man without astrology is like a lamp without oil"

According to the ancients, a planet posited in a particular sign can indicate a weakness, which subject to the right conditions, can manifest into injury, illness or even fatality. It largely depends on the aspects between the planets in the natal chart and the transits triggering them off. For instance, Saturn being posited in the sign of Capricorn and therefore in its dignity as it is ruler of that sign, could show a predisposition to ailments and injuries affecting the bones.

The signs of the zodiac each represent an area of the body, starting with Aries ruling the head, taurus ruling the throat area and so on. The signs continue down the body in their natural order ending with Pisces ruling the feet.

The Natal Chart and Medical Astrology

The main points to be taken into consideration when studying a natal chart from a medical perspective are:

The Sun Sign

- this is the life force so naturally very important. The sun's placement usually shows a weak spot, as in Aries rules the head, Taurus the throat and so on. This applies more so if the Sun is in any way afflicted.

The Moon

- the flowing of the life force throughout the body, the fluids which help maintain the body. Also the emotional well-being. The moon is particularly important in the charts of women as it represents all aspects of the female cycles and motherhood. The moon also represents a weak spot regarding health, especially if afflicted.

If either the sun or the moon are afflicted, it will be of the nature of the afflicting planet and affect the bodily areas governed by the sign of the afflicting planet as well as those of the sun and/or moon.

The Ascendant

- this rules the body as a whole, its appearance and general well-being. Planets afflicting, i.e. in square or opposition or malefic planets conjunct, often show potential harm or illness that can be triggered by transits.

The Sixth House

- this is the house of health, naturally associated with Virgo. The sign on its cusp and its ruling planet is the ruler of health within the birthchart. Planets placed in this house also describe the health and potential illness or accidents. The planet ruling the sign on the cusp of the sixth house will show by its position in the birthchart another weak spot. For example, Capricorn being on the cusp of the sixth house, which is ruled by Saturn, and Saturn being posited in the sign of Pisces shows a likelihood of ailments concerning the feet. Similarly the sign on the cusp itself may show this as in Capricorn ruling the bones and skin.

Aspects to these chart points indicate the likely nature of an illness or of treatment and cure. That is to say that by aspect it can be seen what might be useful to do to ward off ill-health or to provide some sort of cure.

The Decumbiture Chart in Medical Astrology

This is a special kind of chart that is erected based upon the location and time of the onset of illness or injury. It can be used on its own as the chart of the illness for diagnosis and treatment or alongside the birthchart just like a transit chart. The techniques applied to a decumbiture chart are very much the same as those applied in Horary and Electional Astrology.

The Houses in the Decumbiture Chart

In a decumbiture chart the attention is focused on five of the houses in particular. They are:

Ascendant/1st house: the patient's body, general health and vitality

6th house: the patient's disease or injury

7th house: the judgement of the physician or whoever may be attending the patient

8th house: the patient's death

10th house: remedies necessary or appropriate

It is the planetary rulers of these houses that become the significators for each thing.

Also of importance, as in Horary Astrology, is the Moon. As the moon rules the bodily fluids, it represents the flow of the vital life force (the sun) throughout the body. The moon by its motion shows what is happening as it first aspects one planet then another, and by this can show the course of an illness, its treatment and eventual outcome.

Finding the Relevant Significators - The Planets

Only the traditional seven planets (Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn) are used in this kind of medical astrology.

The significator of the patient is the ruler of the sign on the Ascendant. For example: if the ascendant/rising sign is Gemini, the significator will be Mercury as it is the ruling planet of that sign. Mercury would therefore represent the patient and the condition of their general health depending on its placement and aspects received.

The significator of the patient's disease or injury will be the ruler of the sign on the cusp of the sixth house. For example: if the sign occupying the cusp of the sixth house is Scorpio, the significator will be Mars as it is the ruling planet of that sign (traditionally, before the discovery of Pluto and now co-ruler). Mars is associated with heat and therefore feverish conditions, inflammations etc. and by its placement can pinpoint the area of concern. By the condition of Mars in regard to dignity, it is possible to ascertain the seriousness of the illness or injury.

Each of the relevant significators are found as described above. The sequence of the twelve houses are linked with the natural order of the zodiac signs and with regards to anatomy, are so linked with the parts of the body. Therefore a significator for a part of the body will be the ruler of whatever sign happens to be on the cusp of the appropriate house.

For example: the significator of the knees (governed by Capricorn) will be the ruling planet of the sign on the 10th house cusp (naturally Capricorn's house). If Aries should be on the 10th house cusp, the significator would be Mars (ruler of Aries). Therefore Mars would be the significator for the knees.

Strength of Planets

Once the relevant significators have been located the next consideration is their strength. For ease of reference a chart showing the relative strengths and weaknesses is below. The Strength of the planets depends on whether they are in or have dignity. There are lesser dignities by term and face as in Horary and Electional Astrology. Should you wish to go deeper into this, there is a link to the appropriate page for tables of these dignities at the bottom of this page.

Essential Dignities

- please see table below

Dignity - a planet in the sign that it rules and therefore strong.

Exaltation - a planet in the sign where it is strong - this can act like an exaggeration.

Detriment - a planet in the sign that is opposite to the one it rules and therefore weak.

Fall - a planet in the sign that is opposite its exaltation and therefore weak.

Look at the general condition of the patient by locating their significator and ascertaining its strength. i.e. is the Ascendant ruler strong by sign or debilitated?

Assess the energy level of the patient by looking at the condition of the Sun, symbolic of the life force and general vitality.

Assess the emotional level of the patient by looking at the condition of the Moon, as that will show the ability to cope with the emotional side of the illness as well as the general flow of the life force.

Aspects between the Ascendant ruler and the malefic planets of Mars or Saturn indicate a weakening of the patient's vitality. If the Ascendant ruler is retrograde, this also indicates a weakening. Aspects between the Ascendant ruler and the benefic planets of Venus or Jupiter indicate a strengthening of the patient's vitality.

Indicators of which side of the body is affected:

The Eastern Hemisphere of the chart (i.e. the Ascendant side) shows the left side and indicates the left hand, arm, leg or whatever. The Western Hemisphere of the chart (i.e. the Descendant side) shows the right side and indicates the right hand, arm, leg or whatever.

Treatments

As was the basis of Culpeper's practice the main treatment linked to medical astrology is with herbal remedies. Every plant and herb comes under the rulership of a particular planet. Illness associated with a particular planet was treated by a remedy using a plant or herb associated with the same planet. Often two or more plants or herbs were used according to their properties to relieve the symptoms associated with the illness as well as treat the illness itself.

I have compiled an index to the various parts of the anatomy and their ruling signs and planets. Opinion does appear to differ on some of them though, so I have included both where appropriate. This could be due to some planets ruling only a part of an organ for instance, while another planet would rule the remainder. I have also compiled an index to various diseases and the ruling signs and/or planets. Please use the links in the table at the bottom of this page.